Method of reclaiming a well completion brine solutions using an organic chelant

Abstract

A method of reclaiming a well completion brine solution by using an organic chelant that is capable of discriminating between (i) iron and/or non-zinc heavy metals; and (ii) calcium and zinc. The chelant is of the formula: and may be either a neutral compound, a corresponding salt, or a corresponding quaternary salt, wherein: D is F—A (Y 3 ) u (Y 4 ) v ; R is independently selected from C p or C p C(O); C p is a C 1 –C 36 hydrocarbyl group, optionally substituted with one or more substituents selected the group consisting of halogen, hydroxyl, sulfate, CH 2 CO 2 Z or —(CH 2 ) n PO(OZ) 2 groups; each A is independently selected from —N and —P; Y 1 is independently selected from J, —[(F)—A(J)] w Y 6 and R; J, R 1 , Y 2 , Y 3 , Y 4 , Y 5 and Y 6 are independently selected from the group consisting of —H, R, —(F) n CO 2 Z and —(CH 2 ) n PO(OZ) 2 ; each F is independently selected from a C 1 –C 12 hydrocarbyl group, optionally substituted with one or more substituents selected the group consisting of halogen, hydroxyl, sulfate, CH 2 CO 2 Z or —(CH 2 ) n PO(OZ) 2 groups; Z is —H or a balanced counterion of an alkali or alkaline earth metal or NH 4 + ; m is 0 to 7; n is 1 to 7; r+s+t is 1 or 2; u+v is 1 or 2; and w is 0 to 7 provided when m is 0, no more than one of R 1 , Y 1 , Y 2 and Y 5 can be —H.

1. A method of reclaiming a well completion brine comprising the steps of:
 (a.) mixing the brine containing metal impurities with a least one organic chelant for a time sufficient for the chelant to complex a metal and form a complexed metal precipitate, the organic chelant being a neutral compound or a corresponding salt of the formula: 
 
       
         
           
           
               
               
           
         
       
       wherein:
 D is F—A(Y 3 ) n (Y 4 ) v ; 
 R is independently selected from C p  or C p C(O); 
 C p  is a C 1 –C 36  hydrocarbyl group, optionally substituted with one or more substituents selected the group consisting of halogen, hydroxyl, sulfate, CH 2 CO 2 Z or —(CH 2 ) n PO(OZ) 2  groups; 
 each A is independently selected from —N and —P; 
 Y 1  is independently selected from J, —[(F)—A(J)] w Y 6  and R; 
 J, R 1 , Y 2 , Y 3 , Y 4 , Y 5  and Y 6  are independently selected from the group consisting of —H, R, —(F) n CO 2 Z and —(CH 2 ) n PO(OZ) 2 ; 
 each F is independently selected from a C 1 –C 12  hydrocarbyl group, optionally substituted with one or more substituents selected the group consisting of halogen, hydroxyl, sulfate, CH 2 CO 2 Z or —(CH 2 ) n PO(OZ) 2  groups; 
 Z is —H or a balanced counterion of an alkali or alkaline earth metal or NH 4   + ; 
 m is 0 to 7; 
 n is 1 to 7; 
 r+s+t is 1 or 2; 
 u+v is 1 or 2; and 
 w is 0 to 7 
 provided when m is 0, no more than one of R 1 , Y 1 , Y 2  and Y 5  can be —H; and 
 (b.) removing the complexed metal precipitate from the brine 
 
       wherein the metal impurities contain iron and further wherein the complexed metal precipitate contains iron. 
     
     
       2. The method of  claim 1 , wherein s and t are 0 and m is 1 to 7. 
     
     
       3. The method of  claim 2 , wherein the at least one organic chelant is a compound or a corresponding salt of the formula: 
       
         
           
           
               
               
           
         
       
       wherein D represents random repeating blocks of F—A (Y 3 ) u (Y 4 ) v . 
     
     
       4. The method of  claim 3 , wherein the at least one organic chelant is a compound of the formula: 
       
         
           
           
               
               
           
         
       
       wherein R 1  is —H, —(CH 2 ) n PO(OZ) 2  or —(F) n CO 2 Z; and Y 3  and Y 5  are independently selected from —(F) n CO 2 Z, —(CH 2 ) n PO(OZ) 2  and —H; and k is from 1 to 6. 
     
     
       5. The method of  claim 4 , wherein k is 3. 
     
     
       6. The method of  claim 5 , wherein at least one organic chelant is selected from the group consisting of:
 (a.) R—N(CH 2 COOZ)—(CH 2 ) k —NH(CH 2 COOZ); 
 (b.) R—N(CH 2 COOZ)—(CH 2 ) k —N(CH 2 COOZ) 2 ; 
 (c.) R—NH—(CH 2 ) k —N(CH 2 COOZ) 2 ; 
 wherein R is C p  or C p C(O). 
 
     
     
       7. The method of  claim 6 , wherein the C p  group is selected from C 8  to C 36 . 
     
     
       8. The method of  claim 7 , wherein the C p  group is selected from C 12  to C 36 . 
     
     
       9. The method of  claim 8 , wherein the C p  group is selected from C 12  to C 22 . 
     
     
       10. The method of  claim 6 , wherein k is 3, Z is —H and R is a C 14 –C 22  hydrocarbyl group. 
     
     
       11. The method of  claim 4 , wherein the at least one organic chelant is selected from the group consisting of:
 (a.) R—N(CH 2 COOZ)—(CH 2 ) k —NH 2 ; 
 (b.) R—N(CH 2 COOZ)—(CH 2 ) k —NH(CH 2 COOZ) 
 (c.) R—NH—(CH 2 ) k —NH(CH 2 COOZ) 
 (d.) R—N(CH 2 COOZ)—(CH 2 ) k —N(CH 2 COOZ) 2 ; 
 (e.) R—NH—(CH 2 ) k —N(CH 2 COOZ) 2 ; 
 wherein R is C p  or C p C(O). 
 
     
     
       12. The method of  claim 11 , wherein k is 3. 
     
     
       13. The method of  claim 11 , wherein k is 3, R is a C 14 –C 22  hydrocarbyl group and Z is —H. 
     
     
       14. The method of  claim 3 , wherein at least one R 1 , Y 3  or Y 5  is —(F) n CO 2 Z or —(CH 2 ) n PO(OZ) 2 . 
     
     
       15. The method of  claim 2 , wherein the at least one organic chelant is a compound of the formula: 
       
         
           
           
               
               
           
         
       
       wherein Y 3  is —H, C p  or C p C(O), —(F) n CO 2 Z or —(CH 2 ) n PO(OZ) 2 ; and R 1  and Y 5  are independently selected from —(CH 2 ) n PO(OZ) 2 , —(F) n CO 2 Z and —H; and k is from 1 to 6. 
     
     
       16. The method of  claim 15 , wherein k is 3. 
     
     
       17. The method of  claim 15 , wherein the at least one organic chelant is selected from the group consisting of:
 (a.) R—N (R 1 )—(CH 2 ) k —NH(CH 2 COOZ); 
 (b.) R—N (R 1 )—(CH 2 ) k —N(CH 2 COOZ) 2 ; 
 (c.) R—NH—(CH 2 ) k —NY 5 (CH 2 COOZ); 
 (d.) R—N(CH 2 COOZ)—(CH 2 ) k —NHY 5 ; 
 (e.) R—N(CH 2 COOZ)—(CH 2 ) k —NY 5 (CH 2 COOZ). 
 
     
     
       18. The method of  claim 17 , wherein the at least one organic chelant is selected from the group consisting of R—NR 1 —(CH 2 ) k —N(CH 2 COOZ) 2 ; R—N(CH 2 COOZ)—(CH 2 ) k —N(CH 2 COOZ) 2 ; and R—N(CH 2 COOZ)—(CH 2 ) k —NY 5 (CH 2 COOZ). 
     
     
       19. The method of  claim 17 , wherein each Z is —H. 
     
     
       20. The method of  claim 17 , wherein R 1  is —(F) n CO 2 Z or —H. 
     
     
       21. The method of  claim 2 , wherein the at least one organic chelant is a compound of the formula: 
       
         
           
           
               
               
           
         
       
       wherein Y 3  is —H, C p  or C p C(O), —(F) n CO 2 Z or —(CH 2 ) n PO(OZ) 2 ; and R 1  and Y 5  are independently selected from —(F) n CO 2 Z, —(CH 2 ) n PO(OZ) 2  and —H; k is from 1 to 6; and at least one R 1 , Y 3  or Y 5  is —(F) n CO 2 Z or —(CH 2 ) n PO(OZ) 2 . 
     
     
       22. The method of  claim 1 , wherein s, t and m are 0. 
     
     
       23. The method of  claim 22 , wherein the at least one organic chelant is a compound of the formula: 
       
         
           
           
               
               
           
         
       
       wherein R 1  is —H, —(CH 2 ) n PO(OZ) 2  or —(F) n CO 2 Z; and Y 5  is —(F) n CO 2 Z or —(CH 2 ) n PO(OZ) 2 . 
     
     
       24. The method of  claim 23 , wherein the at least one organic chelant is a compound of the formula:
   R—NH(CH 2 COOZ) or R—N(CH 2 COOZ) 2 . 
 
     
     
       25. The method of  claim 1 , wherein the at least one organic chelant is a salt and further wherein s is 0. 
     
     
       26. The method of  claim 25 , wherein the salt is a compound of the formula: 
       
         
           
           
               
               
           
         
       
       wherein R 1  is —H, C p , —(CH 2 ) n PO(OZ) 2  or —(CH 2 ) n CO 2 Z; each of Y 4  and Y 5  are independently selected from —H, —(CH 2 ) n PO(OZ) 2  or —(CH 2 ) n CO 2 Z; X is an anion; and k and n are independently selected from 1 to 6. 
     
     
       27. The method of  claim 1 , further comprising adding to the brine an absorbent, adsorbent or defoamer in an amount sufficient to reduce foaming. 
     
     
       28. The method of  claim 1  wherein at least one J, R 1 , Y 2 , Y 3 , Y 4 , Y 5  or Y 6  is —(F) n CO 2 Z or —(CH 2 ) n PO(OZ) 2 . 
     
     
       29. A method of reclaiming a well completion brine comprising the steps of:
 (a.) mixing the brine containing metal impurities with an organic chelant for a time sufficient for the chelant to complex a metal and form a complexed metal precipitate, wherein the organic chelant is at least one member selected from the group consisting of R—N (R 1 )—(CH 2 ) k —N(CH 2 COOZ) 2 ; R—N(CH 2 COOZ)—(CH 2 ) k —N(CH 2 COOZ) 2 ; and R—N(CH 2 COOZ)—(CH 2 ) k —NY 5 (CH 2 COOZ) 
 
       wherein
 R is independently selected from C p  or C p C(O); 
 C p  is a C 12 –C 36  hydrocarbyl group, optionally substituted with one or more substituents selected from the group consisting of halogen, hydroxyl, sulfate, CH 2 CO 2 Z or —(CH 2 ) n PO(OZ) 2  groups; 
 R 1 and Y   5  are independently selected from —H, R, —(F) n CO 2 Z or —(CH 2 ) n PO(OZ) 2 ; 
 each F is independently selected from a C 1 –C 12  hydrocarbon group, optionally substituted with one or more substituents selected the group consisting of halogen, hydroxyl, sulfate, CH 2 CO 2 Z or —(CH 2 ) n PO(OZ) 2  groups; 
 Z is —H or a balanced counterion of an alkali or alkaline earth metal or NH 4   + ; 
 n is 1 to 7; and 
 k is from 1 to 6; and 
 (b.) removing the complexed metal precipitate from the brine wherein the metal impurities contain iron and further wherein the complexed metal precipitate contains iron.